S04E08: 'Silence In The Library'

A psychologist called Doctor Moon analyses the mind of a young girl who has visions of a library in the future - only for The Doctor and Donna to come bursting in.

The Doctor and Donna arrive on a planet in the future that is an entire library with every book ever written. It is seemingly deserted but The Doctor checks the computer and discovers a million million non-human lifeforms are present.

A 'Node' - a statue with a real human face - relays a message that warns the time travellers to "stay out of the shadows". The lights in the library start to dim and the pair run for safety. The Doctor finds an oval-shaped security camera - which the young girl can see through in her mind. Donna is shocked to learn that the Nodes have real human faces from deceased people.

A team of archaeologists arrive on the library. The team leader River Song appears to know The Doctor from the future and hints that they have some romantic involvement. Donna sympathises with Evangelista, a pretty girl who views herself as dim. Around them the library is getting darker.

The Doctor reveals that a force called Vashda Nerada lurks in the shadows and it can instantly strip flesh that falls into the infected darkness.

The team tries to contact the library's computer and this results in the telephone in the young girl's house ringing. The Doctor then appears on her television and communicates with her.

Evangelista investigates a nearby room as the others discover that thousands perished in the library, but no remains are found. Evangelista is later found dead, killed by a shadow and only remaining in skeletal form. A 'data ghost' built into her spacesuit enables her harrowing thoughts to be artificially kept alive for a few moments.

Doctor Moon tells the girl that "the real world is a lie" and that the library is real and people need her to save them.

The Doctor notices that one of the two archaeologists called Dave has two shadows around him. He becomes infected under his helmet and is soon a skeleton. The Doctor beams Donna to apparent safety on board the Tardis but she screams and disappears.

The remains of Dave, possessed by the shadows, stalks the library dwellers. The Doctor then comes across a Node - with Donna's face.